Compressor

ABSTRACT

The present invention relates to a compressor used in an air conditioner of a vehicle. In the present invention, an oil separation chamber and a discharge chamber are formed in one side of a discharge chamber of a compressor, a cylindrical oil separation conduit is formed between the oil separation chamber and the discharge chamber. At the same time, one discharge passage is formed such that refrigerant supplied from the front and rear discharge chambers is collected and oil is separated from the refrigerant, so that the oil is separated from the compressed refrigerant and returns to a swash plate chamber, thereby improving lubricity in the swash plate chamber.

This Nonprovisional application claims priority under 35 U.S.C. § 119(a) on Patent Application No(s). 2007-0055578 filed in Korea, Republic of on Jun. 7, 2007, the entire contents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a compressor, and more particularly, to a compressor, which is to separate oil from refrigerant compressed in a cylinder bore and discharged to the outside and then to return the oil to a swash plate chamber, thereby improving lubricity in the swash plate chamber.

2. Description of the Related Art

Generally, a compressor for a vehicle inhales refrigerant gas evaporated in an evaporator and discharged therefrom, converts the refrigerant gas into an easily liquefied state with high pressure and high temperature, and then discharges the refrigerant gas to a condenser.

Such a compressor is classified into various kinds: a swash plate type compressor in which a piston is reciprocated by rotation of an inclined swash plate, a scroll type compressor in which compression is made by rotation of two scrolls, and a vane rotary type compressor in which compression is made by a rotating vane.

Among them, a reciprocation type compressor that compresses refrigerant by means of reciprocation of a piston includes a crank type compressor and a plate type compressor in addition to the swash plate type compressor. The swash plate type compressor is also classified into a fixed capacity swash plate type compressor and a variable-capacity swash plate type compressor depending on its usage.

FIGS. 1 and 2 show a conventional fixed capacity swash plate type compressor, which will be explained with reference to the figures.

As shown in FIG. 1, a front housing 13 and a rear housing 14 are coupled to a pair of cylinder blocks 11 and 12, and a discharge chamber 131 is formed in the front housing 13. The rear housing 14 is formed with a discharge chamber 141 and a suction chamber 142.

A valve plate 15, a reed forming plate 16 and a retainer forming plate 17 are installed between the cylinder block 11 and the front housing 13.

In addition, a valve plate 18, a reed forming plate 19 and a retainer forming plate 20 are provided between the cylinder block 12 and the rear housing 14. The valve plates 15 and 18 are formed with discharge holes 151 and 181, and the reed forming plates 16 and 19 are formed with discharge reeds 161 and 191. The discharge reeds 161 and 191 open or close the discharge holes 151 and 181.

A driving shaft 21 is rotatably supported to the cylinder blocks 11 and 12. The driving shaft 21 is inserted through shaft support holes 11 and 121 bored through the cylinder blocks 11 and 12, and the driving shaft 21 is directly supported to the cylinder blocks 11 and 12 through the shaft support holes 11 and 121.

The driving shaft 21 is provided with a swash plate 23. The swash plate 23 is received in a swash plate chamber 24 between the cylinder blocks 11 and 12. A thrust bearing 25 is installed between an end surface of the cylinder block 11 and a base 231 of the swash plate 23.

As seen from FIG. 2, a plurality of cylinder bores 27 and 28 are formed in the cylinder block 11 to be arranged around the driving shaft 21, and a piston 29 is received in the cylinder bores 27 and 28.

As shown in FIG. 1, the rotation of the swash plate 23, which rotates together with the driving shaft 21, is transmitted to the piston 29 through a shoe 30, and the piston 29 reciprocates forward and backward inside of the cylinder bores 27 and 28. The piston 29 partitions the interior of the cylinder bores 27 and 28 into compression chambers 271 and 281.

The driving shaft 21 is directly supported to the cylinder blocks 11 and 12 through circumferential sealing surfaces 112 and 122.

A supply passage 211 is formed in the driving shaft 21. A start end of the supply passage 211 is positioned at an end inside of the driving shaft 21 and communicates with the suction chamber 142 in the rear housing 14. The driving shaft 21 is formed with introduction passages 31 and 32 to communicate with the supply passage 211.

As shown in FIG. 2, a suction passage 33 is formed in the cylinder block 11 to communicate with the cylinder bore 27 and a shaft support hole 111 in succession. An inlet 331 of the suction passage 33 is opened on the circumferential sealing surface 112.

Along with the rotation of the driving shaft 21, outlets 311 and 321 of the introduction passages 31 and 32 intermittently communicate with the inlets 331 and 341 of the suction passages 33 and 34.

When the cylinder bore 21 is in an intake stroke state (i.e., in a stroke state where the piston 29 moves from the left side to the right side in FIG. 1), the outlet 311 communicates with the inlet 331 of the suction passage 33. When the cylinder bore 27 is in an intake stroke state, the refrigerant in the supply passage 211 of the driving shaft 21 is inhaled into the compression chamber 271 of the cylinder bore 27 via the introduction passage 31 and the suction passage 33.

When the cylinder bore 27 is in a discharge stroke state (i.e., in a stroke state where the piston 29 moves from the right side to the left side in FIG. 1), the outlet 311 is blocked from the inlet 331 of the suction passage 33. When the cylinder bore 27 is in a discharge stroke state, the refrigerant in the compression chamber 271 pushes away a discharge reed 161 from the discharge hole 151 and is then discharged to the discharge chamber 131, and the refrigerant discharged to the discharge chamber 131 is discharged to the outside. The refrigerant discharged to the outside returns to the suction chamber 142.

In such a conventional compressor, during the compression stroke of the cylinder bores 27 and 28, refrigerant and oil are partially received in the swash plate chamber 24 through circumferential surfaces of the cylinder bores 27 and 28 and the cylinder 29, but the refrigerant compressed in the cylinder bores 27 and 28 is mostly discharged to the outside through the discharge chamber 131. Also, together with the refrigerant discharged to the outside, the oil introduced into the cylinder bores 27 and 28 mostly escapes to the outside.

Accordingly, there are problems in that the swash plate chamber 24 lacks lubricant and lubricant may be not supplied sufficiently to a portion requiring lubricant, such as a region between the swash plate 23 and the shoe 30 which transmits the rotation of the swash plate 23 to the piston 29.

A solution for such problems is disclosed in U.S. Pat. No. 6,015,269B. According to the document, a variable capacity type compressor includes a configuration for separating oil from discharge refrigerant, and a configuration for returning the separated oil to a crank chamber via a small hole. However, in such a prior art, the discharge refrigerant may be introduced into the crank chamber together with oil, and it is difficult to sufficiently throttle oil only with the small hole. Thus, a variable capacity type compressor with such configurations may cause some problems in operation, such as misoperation.

In addition, U.S. Pat. No. 7,204,098 discloses a variable capacity compressor which has a configuration for introducing a discharge refrigerant into a separation chamber in two directions through first and second communication passages and rotating the discharge refrigerant thereby separating oil from the refrigerant. However, it is very difficult to form the two communication passages in the two directions as described above, and it is also difficult to separate only oil from refrigerant and return it, as in U.S. Pat. No. 6,015,269B.

SUMMARY OF THE INVENTION

The present invention is conceived to solve the aforementioned problems in the prior art. An object of the present invention is to provide a compressor wherein an oil separation chamber and a discharge chamber are formed in one side of a discharge chamber, and a cylindrical oil separation conduit is formed between the oil separation chamber and the discharge chamber, so that oil is separated from compressed refrigerant and returns to a swash plate chamber, thereby improving lubricity in the swash plate chamber.

To this end, according to the present invention, there is provided a compressor, in which a swash plate rotating in a swash plate chamber formed in a cylinder block is coupled to a driving shaft, a refrigerant suction passage for allowing refrigerant to be inhaled therethrough is formed in one side of the swash plate chamber, pistons respectively received in a plurality of cylinder bores arranged annularly around the driving shaft are reciprocated in cooperation with the rotation of the swash plate, the refrigerant inhaled into the swash plate chamber through the refrigerant suction passage is supplied to the respective cylinder bores, and the refrigerant supplied to the cylinder bores is compressed in the cylinder bores by the pistons and then flows out through front and rear discharge chambers of the cylinder block. The compressor includes a communication passage formed to communicate with both the front and rear discharge chambers to collect refrigerant supplied from the front and rear discharge chambers, the communication passage being connected to one end of a discharge passage; an oil separation chamber formed to be connected to the other end of the discharge passage and communicate with the communication passage through the discharge passage, the oil separation chamber being provided therein with a cylindrical oil separation conduit for centrifugally separating oil and refrigerant introduced therein from each other; a discharge chamber positioned at one side of the oil separation chamber to receive the refrigerant separated from the oil by the oil separation conduit and then discharge the refrigerant to the outside; and an oil return unit formed to communicate with the oil separation chamber and returning the oil separated from the refrigerant by the oil separation conduit to the swash plate chamber.

Preferably, the discharge passage is formed slantingly at a predetermined angle with respectively to a flow direction of the refrigerant flowing in the communication passage so that the refrigerant introduced through the discharge passage rotates along an outer peripheral surface of the oil separation conduit.

The oil return unit may include an oil storage chamber formed at one side of the oil separation chamber and storing the oil separated in the oil separation chamber; an oil decompression portion having one end formed in communication with the oil storage chamber to decompress the oil supplied from the oil storage chamber; and an oil retrieve passage formed in communication with the oil decompression portion and the swash plate chamber to cause the oil passing through the oil decompression portion to be supplied to the swash plate chamber again, wherein the oil decompression portion is an orifice tube having one side communicating with the oil storage chamber and the other end communicating with the oil retrieve passage.

Preferably, the refrigerant suction passage is formed in the driving shaft, a plurality of suction passages are formed in the cylinder blocks so that the refrigerant inhaled from the swash plate chamber into a refrigerant suction channel formed in the driving shaft is inhaled into each cylinder bore by allowing the refrigerant suction channel and the cylinder bores to subsequently communicate with each other according to the rotation of the driving shaft, and an inlet of the refrigerant suction channel is formed to pass through a hub of the swash plate and one side of the driving shaft.

Preferred embodiments of the present invention will be described in more detail with reference to the following drawings. Accordingly, the features and advantages of the present invention will become more apparent.

BRIEF DESCRIPTION OF THE DRAWINGS

The above objects, and other features and advantages of the present invention will become more apparent after a reading of the following detailed description when taken in conjunction with drawings, in which:

FIG. 1 is a side sectional view showing a conventional compressor;

FIG. 2 is a sectional view taken along line B-B of FIG. 1;

FIG. 3 is a perspective view showing a cylinder block of a preferred embodiment of a compressor according to the present invention;

FIG. 4 is a side sectional views showing the embodiment of the compressor according to the present invention; and

FIG. 5 is a sectional view showing a rear cylinder block of the embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Hereinafter, a preferred embodiment of a compressor according to the present invention will be described in detail with reference to the accompanying drawings.

Referring to the figures, a compressor 400 of this embodiment includes cylinder blocks 430 and 440 defining an external appearance and a framework of the compressor, and a swash plate 460 is integrally coupled to a driving shaft 450 and rotated in a swash plate chamber 436 formed in the cylinder blocks 430 and 440.

A refrigerant suction passage (not shown) for inhaling refrigerant is formed in one side of the swash plate chamber 436, and a plurality of cylinder bores 431 and 441 are arranged annularly around the driving shaft 450.

Also, pistons 470 respectively received in the plurality of cylinder bores 431 and 441 are reciprocated in cooperation with the rotation of the swash plate 460. Accordingly, the refrigerant inhaled into the swash plate chamber 436 through the refrigerant suction passage is supplied to the cylinder bores 431 and 441. Also, the refrigerant supplied to the cylinder bores 431 and 441 is compressed in the cylinder bores 431 and 441 by the pistons 470 and then flows out through front and rear discharge chambers 411 and 421 of the cylinder blocks 430 and 440.

At this time, an oil separation chamber 520 is formed in the cylinder blocks 430 and 440 to communicate with both the front and rear discharge chambers 411 and 421. An oil separation conduit 530 is provided inside of the oil separation chamber 520, so that the refrigerant and oil introduced through the discharge chambers 411 and 421 are centrifugally separated.

Here, the aforementioned components will be explained in more detail. Both sides of the driving shaft 450 are rotatably installed to shaft support holes 433 and 443 of the front and rear cylinder blocks 430 and 440. At this time, one end of the driving shaft 450 extends to pass through the front housing 410 and coupled with an electromagnetic clutch (not shown), and the other end thereof communicates with a refrigerant storage chamber 424 of the rear housing 420, which will be described below.

The swash plate 460 rotating inside the swash plate chamber 436 is slantingly coupled to the driving shaft 450. Also, a refrigerant suction channel 451 for allowing the swash plate chamber 436 to communicate with the cylinder bores 431 and 441 is formed in the driving shaft 450 such that the refrigerant inhaled into the swash plate chamber 436 through a suction port (not shown) of the rear cylinder block 440 can flow into the cylinder bores 431 and 441.

The refrigerant suction channel 451 has an inlet 452 formed to communicate with the swash plate chamber 436 and outlets 453 formed to communicate with the suction passages 432 and 442 of the front and rear cylinder blocks 430 and 440.

Here, the inlet 452 of the refrigerant suction channel 451 is formed to pass through a hub 461 of the swash plate 460 and one side of the driving shaft 450.

Meanwhile, the refrigerant suction channel 451 may have the inlet 452 formed only in one side of the driving shaft 450, or two inlets formed in opposite directions.

In addition, the outlets 453 of the refrigerant suction channel 451 are formed at both sides of the refrigerant suction channel 451 in opposite directions, so that refrigerant can be inhaled simultaneously into the cylinder bores 431 and 441 provided at both sides of the swash plate chamber 436 when the driving shaft 450 rotates.

Of course, the directions of the outlets 453 of the refrigerant suction channel 451 formed in the driving shaft 450 may be changed depending on the design such as the number of the pistons 470.

In addition, the plurality of cylinder bores 431 and 441 are formed in the front and rear cylinder blocks 430 and 440 at both the sides of the swash plate chamber 436 therein, and the shaft support holes 433 and 443 are formed at the center of the swash plate chamber 436 so as to rotatably support the driving shaft 450.

The suction passages 432 and 442 for allowing the shaft support holes 433 and 443 and the cylinder bores 431 and 441 to communicate with each other are formed in the front and rear cylinder blocks 430 and 440 such that the refrigerant inhaled into the refrigerant suction channel 451 of the driving shaft 450 may be inhaled into the cylinder bores 431 and 441 subsequently when the driving shaft 45° rotates.

In addition, one outer surface of the front and rear cylinder blocks 430 and 440 is formed with a suction port (not shown) communicating with the swash plate chamber 436 so as to supply external refrigerant to the swash plate chamber 436 and a discharge hole (not shown) communicating with the discharge chambers 411 and 421 so as to discharge refrigerant in the discharge chambers 411 and 421 of the front and rear housings 410 and 420 to the outside.

Thus, discharge passages 434 and 444 connecting the discharge chambers 411 and 421 of the front and rear housings 410 and 420 with the discharge hole are formed in the front and rear cylinder blocks 430 and 440, and the discharge passages 434 and 444 are respectively connected to a communication passage 510.

The communication passage 510 communicates with the discharge passages 434 and 444, so that all of refrigerant compressed in the plurality of cylinder bores 431 and 441 is gathered at this communication passage 510 through the discharge passages 434 and 444.

The refrigerant gathered at the communication passage 510 is inhaled through a discharge passage 511 into the oil separation chamber 520 formed at one side of the communication passage 510.

The oil separation conduit 530 for centrifugally separating only oil from the refrigerant introduced through the discharge passage 511 is formed in the oil separation chamber 520. In this embodiment, the oil separation conduit 530 has one end communicating with the oil separation chamber 520 and the other end communicating with a discharge chamber 540, which will be described later.

The discharge passage 511 is formed slantingly at a predetermined angle with respect to a flow direction of the refrigerant that flows in the communication passage 510. This is to enable the refrigerant introduced through the discharge passage 511 to rotate and flow along an outer peripheral surface of the oil separation conduit 530. Accordingly, the refrigerant introduced through the discharge passage 511 is separated from the oil by centrifugal force while rotating around the oil separation conduit 530.

More specifically, the refrigerant introduced through the discharge passage 511 rotates around the oil separation conduit 530, and at this time, the oil with relatively greater specific weight is moved outward and then moved downward due to its weight toward an oil return unit 560, which will be described later, and the refrigerant with relatively smaller specific weight is moved to the discharge chamber 540 through an inner hollow of the oil separation conduit 530.

The refrigerant introduced into the discharge chamber 540 is delivered to the outside through the discharge hole.

Meanwhile, the oil separated from the refrigerant by the oil separation conduit 530 is delivered to the oil return unit 560.

The oil return unit 560 is to return the oil, which is separated from the refrigerant at the oil separation chamber 520, to the swash plate chamber again, and includes an oil storage chamber 561, an oil decompression portion 562 and an oil retrieve passage 563.

As shown in FIGS. 3 and 5, the oil storage chamber 561 is formed at one side of the oil separation chamber 520 and stores the oil separated in the oil separation chamber 520. Since the oil compressed at high pressure in the cylinder bores 431 and 441 is continuously introduced into the oil storage chamber 561, the oil storage chamber 561 is maintained as a high pressure region.

In addition, the oil decompression portion 562 is formed to communicate with the oil storage chamber 561 and decreases the pressure of the oil supplied from the oil storage chamber 561. In this embodiment, the oil decompression portion 562 is configured in the formed of an orifice tube, which has one end communicating with the oil storage chamber 561 and the other end communicating with the oil retrieve passage 563 and has an oil flow passage with its diameter varying. However, various oil decompressing devices may also be used instead of the orifice tube if they can decrease oil pressure.

The oil passing through the orifice tube is changed into low-pressure oil since oil pressure is decreased according to the varying diameter of the oil flow passage. Also, the oil decompressed through the oil decompression portion 562 is moved to the swash plate chamber 436 through the oil retrieve passage 563 formed on the cylinder blocks 430 and 440.

The oil retrieve passage 563 is formed in the front and rear cylinder blocks 430 and 440 and has one end communicating with the oil decompression portion 562 and the other end communicating with the swash plate chamber 436.

Hereinafter, an operation state of the compressor of this embodiment according to the flow of refrigerant will be explained as follows.

In the compressor 400 according to this embodiment, if the driving shaft 450 selectively receiving power from an electronic clutch (not shown) rotates, the swash plate 460 is rotated. At this time, the plurality of pistons 470 cooperating with the rotation of the swash plate 460 are reciprocated inside of the cylinder bores 431 and 441 of the front and rear cylinder blocks 430 and 440 and repeatedly inhale and compress refrigerant.

The refrigerant supplied into the cylinder bores 431 and 441 is compressed by means of the pistons 470 inside of the cylinder bores 431 and 441 during a compression stroke and then discharged to the discharge chambers 411 and 421 of the front and rear housings 410 and 420. Thereafter, the discharged refrigerant is introduced into the communication passage 510 through the discharge passages 434 and 444 of the front and rear cylinder blocks 430 and 440.

The refrigerant gathered at the communication passage 510 is supplied to the oil separation chamber 520 through the discharge passage 511, and at this time, the refrigerant supplied to the oil separation chamber 520 is separated from oil while rotating around the oil separation conduit 530.

Then, the refrigerant separated from the oil is moved to the discharge chamber 540 through the hollow of the oil separation conduit 530 and then discharged to the outside through the discharge hole.

Meanwhile, the oil separated from the refrigerant by the oil separation conduit 530 is introduced into the oil storage chamber 561.

The oil introduced into the oil storage chamber 561 is introduced into the oil decompression portion 562, and the high-pressure oil passes through the orifice tube in the oil decompression portion 562 whereby the pressure of the oil decreases.

The low pressure oil is introduced into the oil retrieve passage 563 and then introduced into the swash plate chamber 436 again through the oil retrieve passage 563.

As described above, the fixed capacity swash plate type compressor 400 with a driving shaft-integrated suction rotary valve, in which the refrigerant suction channel 451 is formed in the driving shaft 450 and the refrigerant in the swash plate chamber 436 is directly supplies to the cylinder bores 431 and 441 has been explained in the present invention. However, the present invention is not limited thereto, but may also be applied to various kinds of compressors such as an electromotive compressor in the same manner and configuration and have the same effects.

As described above, according to the compressor of the present invention, refrigerant supplied through the front and rear discharge chambers is gathered into one communication passage, the gathered refrigerant is separated from oil using the oil separation conduit installed between the oil separation chamber and the discharge chamber, and then the separated oil is supplied to the swash plate chamber through the oil return unit again, thereby improving lubricity of the swash plate chamber.

In addition, according to the present invention, high-pressure refrigerant, as external refrigerant, is supplied via the oil separation chamber and the discharge chamber, which are formed in the compressor, so that it is possible to reduce noise by decreasing pulsating pressure of the refrigerant.

Also, the oil decompression portion using an orifice tube is formed in the oil return unit to prevent discharge refrigerant from being introduced, and at this time, the oil to be supplied to the swash plate chamber is decompressed to low pressure in advance and then supplied to the swash plate chamber again, so that it is possible to prevent the refrigerant with high pressure from being directly supplied to the swash plate chamber, thereby ensuring excessive force not to be applied to the internal structure of the compressor and thus improving durability of the compressor.

In addition, according to the present invention, a discharge passage for discharging refrigerant to the oil separation chamber is formed between the oil separation chamber and the communication passage, wherein only the single discharge passage is formed along a straight passage slantingly with respect to the lengthwise direction of the communication passage, whereby the compressor can be easily produced.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skill in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. 

1. A compressor, comprising: cylinder blocks positioned between front and rear housing and having a swash plate chamber provided therein, the front and rear housing defining external appearances of both ends of the compressor; a driving shaft having a swash plate rotatably installed in the swash plate chamber, the swash plate chamber having a refrigerant suction passage formed at one side thereof, the refrigerant suction passage allowing refrigerant to be inhaled therethrough; pistons respectively received in a plurality of cylinder bores arranged annularly around the driving shaft and reciprocated in cooperation with the rotation of the swash plate to compress refrigerant supplied to the cylinder bores, whereby the refrigerant flows out through front and rear discharge chambers of the cylinder blocks; a communication passage formed to communicate with both the front and rear discharge chambers; an oil separation chamber provided therein with a cylindrical oil separation conduit for centrifugally separating oil and refrigerant introduced therein from each other; one discharge passage allowing the communication passage to communicate with the oil separation chamber so that refrigerant supplied from the front and rear discharge chambers is collected through the communication passage and then discharged to the oil separation chamber; a discharge chamber positioned at one side of the oil separation chamber to receive the refrigerant separated from the oil by the oil separation conduit and then discharge the refrigerant to the outside; and an oil return unit formed to communicate with the oil separation chamber and returning the oil separated from the refrigerant by the oil separation conduit to the swash plate chamber.
 2. The compressor as claimed in claim 1, wherein the discharge passage is formed slantingly at a predetermined angle with respectively to a flow direction of the refrigerant flowing in the communication passage so that the refrigerant introduced through the discharge passage rotates along an outer peripheral surface of the oil separation conduit.
 3. The compressor as claimed in claim 1, wherein the oil return unit includes: an oil storage chamber formed at one side of the oil separation chamber and storing the oil separated in the oil separation chamber; an oil decompression portion having one end formed in communication with the oil storage chamber to decompress the oil supplied from the oil storage chamber; and an oil retrieve passage formed in communication with the oil decompression portion and the swash plate chamber to cause the oil passing through the oil decompression portion to be supplied to the swash plate chamber again, wherein the oil decompression portion is an orifice tube having one side communicating with the oil storage chamber and the other end communicating with the oil retrieve passage.
 4. The compressor as claimed in claim 1, wherein the refrigerant suction passage is formed in the driving shaft, a plurality of suction passages are formed in the cylinder blocks so that the refrigerant inhaled from the swash plate chamber into a refrigerant suction channel formed in the driving shaft is inhaled into each cylinder bore by allowing the refrigerant suction channel and the cylinder bores to subsequently communicate with each other according to the rotation of the driving shaft, and an inlet of the refrigerant suction channel is formed to pass through a hub of the swash plate and one side of the driving shaft. 